Scale and pattern of broadnose sevengill shark Notorynchus cepedianus movement in estuarine embayments.

The detailed movements of 32 acoustically tagged broadnose sevengill shark Notorynchus cepedianus were documented in and around north-east Pacific Ocean estuarine embayments from 2005 to 2007. Arrangements of passive acoustic receivers allowed analysis of movement at several spatial scales, with sex and size examined as possible factors influencing the pattern and timing of these movements. Notorynchus cepedianus exhibited a distinctly seasonal pattern of estuary use over three consecutive years, entering Willapa Bay in the spring, residing therein for extended periods of time during the summer and dispersing into nearshore coastal habitats and over the continental shelf during the autumn. Notorynchus cepedianus within Willapa Bay showed spatio-temporal patterns of segregation by size and sex, with males and small females using peripheral southern estuary channels early in the season before joining large females, who remained concentrated in central estuary channels for the entire season. Individuals displayed a high degree of fidelity not only to Willapa Bay (63% were documented returning over three consecutive seasons), but also to specific areas within the estuary, showing consistent patterns of site use from year to year. Cross-estuary movement was common during the summer, with most fish also moving into an adjacent estuarine embayment for some extent of time. Most winter and autumn coastal detections of N. cepedianus were made over the continental shelf near Oregon and Washington, U.S.A., but there were also examples of individuals moving into nearshore coastal habitats further south into California, suggesting the feasibility of broad-scale coastal movements to known birthing and nursery grounds for the species. These findings contribute to a better understanding of N. cepedianus movement ecology, which can be used to improve the holistic management of this highly mobile apex predator in regional ecosystems.

Nitric oxide: a primer for the practicing anesthetist.

Nitric oxide (NO) is receiving interest because of its use in patients with acute respiratory distress syndrome. Because more studies are being conducted, researchers are discovering a vast array of physiological effects attributable to NO. NO has been implicated as having a role in the endogenous regulation of blood pressure; smooth, skeletal, and cardiac muscle relaxation; renal and immune system functioning; and selective pulmonary vasodilation. This article looks at the pharmacological and physiological effects of NO and its current use in the clinical setting.

Insights into the cellular mechanisms of erythropoietin-thrombopoietin synergy.

Using suspension cultures of purified bone marrow CD34+ cells, we have analyzed the effects of the combination of erythropoietin (Epo) and thrombopoietin (Tpo) on the in vitro differentiation toward erythropoiesis and thrombopoiesis. The number of CD41+ cells that accumulated over 2 weeks of culture, as well as the number of globin+ cells in the same cultures, was found to be significantly higher with the Epo+Tpo combination compared to either cytokine alone. No evidence was found that Tpo affected the differentiative action of Epo. Instead, there was a significant expansion of erythroid progenitors, both erythroid colony-forming and burst-forming units (CRU-E and BFU-E), by 7 days in culture, suggesting a proliferative effect of Tpo on erythroid cells in vitro. To determine the phenotypic features of erythroid progenitor cells which were targets of Tpo's action, and specifically to inquire whether the effect was directed mainly toward bipotent erythroid/megakaryocytic (E+Mk) progenitors, we isolated subsets enriched for both erythroid and megakaryocytic progenitors from CD34+ cells. We found that 1) BFU-E and CFU-Mk co-segregate in the subset of CF34+ cells that is negative for the phosphatase isoform CD45RA; 2) the presence of CD41 on this subset appears to segregate late erythroid and late CFU-Mk from early erythroid and early CFU-Mk, which are CD41-negative; 3) bipotent erythroid/Mk progenitors, studied by single-cell culture assays, were found mainly in the CD41+ and rarely in the CD41- subsets which included more multipotent progenitors; 4) by comparing the frequencies of pure erythroid or pure megakaryocytic progenitors to that of bipotent E+Mk progenitors, we conclude that the erythroid-enhancing effect of Tpo is directed mainly toward pure erythroid progenitors expressing CD41 and Mpl, as suggested by independent experiments employing anti-Mpl antibody, rather than only on bipotent E+Mk progenitors.

Shear modulus-temperature meltdown profiles of gelatin and pectin gels. A cascade theory description.

In this paper, a cascade theory approach to biopolymer gelation is developed to describe variation of the shear modulus with temperature for thermoreversible gels. The broadness of this 'melting transition' is seen to depend crucially on the enthalpy of cross-linking, while the critical gel melting temperature is determined by additional factors such as the entropy of cross-linking, the polymer concentration, the molecular weight, and the number of cross-linking sites. On using the model to fit experimental data for specific gelatin and pectin systems, it was found that the behaviour of gelatin (sharp melting transition and low melting temperature) is a consequence of the large negative enthalpy and entropy of cross-linking, while, in contrast, the broad melting transition and high melting point of the pectin system are consistent with much smaller negative values for these parameters.

Mood, cognition and cortisol: their temporal relationships during recovery from depressive illness.

Single-case methodology, using cross-lagged panel correlations, was applied to study the order of change in mood, cognition and cortisol concentration in eight in-patients with a diagnosis of major, endogenous depression. Daily measures included: two visual analogue scales measuring depressed mood and general feeling of unwellness; cortisol concentration in saliva (sampled four times a day) and in 24-h urine; two cognitive scales, the Automatic Thoughts Questionnaire and the Cognitive Style Test. The results relating to the temporal relationship between biological and psychological data were ambiguous as the pattern of change was inconsistent among individuals. Group data indicated that changes in feeling unwell preceded changes in early evening salivary cortisol and changes in negative automatic thoughts preceded changes in day and early evening salivary cortisol. Psychological variables and cortisol concentrations were generally negatively correlated within individuals indicating that over the short recovery period improving mood and cognition were associated with increasing levels of cortisol. A more consistent pattern of precedence of change was obtained for mood and cognition: negative cognitive style predicted changes in both mood measures and feeling unwell predicted changes in negative automatic thoughts.

Effects of benactyzine on an equilibrium and multiple response task in rhesus monkeys.

Five Macaca mulatta were tested for performance changes following exposure to benactyzine HCl (intramuscular) at four doses ranging from 0.054 mg/kg to 1.7 mg/kg. Subjects simultaneously operated a primate equilibrium platform and responded to a multiple alternative reaction task. Performance on both the continuous and discrete tasks were progressively degraded as benactyzine dose increased. At the higher doses it appeared that they concentrated their efforts on one of the tasks while neglecting the other. Thus, performance on one task might be normal and at the same time performance on another task would be degraded.